José Mourinho says Manchester United would be "on the edge" of surrendering the Premier League title if they were to lose to the leaders, Arsenal, at Old Trafford on Sunday.

United would slip to 11 points off the pace with a first home defeat by Arsenal since 2006 but Mourinho, the Chelsea manager, maintained that even in the worst-case scenario, everything would not be lost for them.

"It's on the edge [with a loss] but United is United," Mourinho said. "So even 10, 11 points … I wouldn't say it's over for them. If they lose … in this Premier League, I don't think it's impossible for them to be champions."

Sir Alex Ferguson, the former United manager, said in his autobiography that Mourinho had made his club approach the league season differently. Before the Portuguese arrived at Chelsea for the first time in 2004, United had sought to pace themselves over the course of the season, building up to a strong finish.

But Mourinho's flying starts in 2004 and 2005 made Ferguson realise that United had to sprint from the outset. David Moyes, Ferguson's successor, has endured a mixed start to the season, although his team have now gone eight matches in all competitions without defeat.

"He [Ferguson] told me that," Mourinho said. "He used some funny words, like saying the championship was a marathon but after [Chelsea] it became a marathon in a sprint. I know it's true that, after that, United felt that they needed a different approach.

"We pushed them to a different level than they were in 2004 and 2005, when it was quite comfortable for us to win our Premierships."